Surfactant adsorption cationic

Rutland M W and Parker J L 1994 Surface forces between silica surfaces in cationic surfactant solutions adsorption and bilayer formation at normal and high pH Langmuir 0 1110-21... 

Tarazona A, Kreisig S, Koglin E and Schwuger M J 1997 Adsorption properties of two cationic surfactant classes on silver surfaces studied by means of SERS spectroscopy and ab initio calculations Prog. Colloid Polym. Sol. 103 181-92... 

The NDR and the oscillation appear only in the presence of cationic surfactant and not in the presence of anionic surfactant, suggesting that the NDR arises from electrostatic adsorption of a cationic surfactant on a (negatively polarized) Cu-Sn... 

Adsorption of corrosion inhibitors or cationic surfactants can reduce sandstone formation permeability. Alcohols can be used to remove corrosion inhibitors from rock surfaces. Oil-soluble corrosion inhibitors may be dissolved by organic solvents such as xylene or toluene containing a mutual solvent, most often ethylene glycol monobutyl ether, EGMBE (167). Aqueous fluids containing 5-10% EGMBE can be used to dissolve cationic surfactants. 

Xu SH, Boyd SA (1995) Cationic surfactant adsorption by swelling and nonswelling layer silicates. Langmuir 1 2508-2514... 

The main difficulties in CE analysis of cationic surfactants arise from their strong adsorption to the capillary wall and their ability to form micelles at low concentrations. The addition of organic modifiers in high amounts or separation in absolutely non-aqueous media disrupt micelle formation within the sample and also effectiveness of the organic modifier to disrupt micelles of alkylbenzyl dimethyl ammonium... 

One of the main problems to be solved in the analysis of cationic surfactants is the strong adsorption of the surfactant to glassware, tubing and apparatus. To avoid losses, the solvent system used should contain a substantial percentage of organic solvent. Additionally, mobile phases containing more than 20-25% methanol will help to inhibit micelle formation [46]. 

This Gemini cationic surfactant could not be recovered from samples of biodegradation experiments performed in a lab-scale aerobic bioreactor [50] either because of complete biodegradation (mineralisation) or because of irreversible adsorption at the surface of the biodegradation device. 

It is also noteworthy that the surface tension of mixed solutions of anionic and cationic surfactants is controlled by the activity of the salt (38). These results indicate that, in adsorption of an ionic surfactant at the solution surface, the accompanying adsorption of the counter ion also plays an important role. 

MEKC is also performed using cationic, nonionic, and zwitterionic surfactants. Widely employed are cationic surfactant consisting of a long chain tetralkylammonium salt, such as cetyltrimeth-ylammonium bromide, which causes the reversal of the direction of the EOE, due to the adsorption of the organic cation on the capillary wall. Other interesting options include the use of mixed micelles resulting from the simultaneous incorporation into the BGE of ionic and nonionic or ionic and zwitterionic surfactants. Chiral surfactants, either natural as bile salts [207] or synthetic [208] are employed for enantiomer separations. 

The surface tension data given in Figure 3.5 was obtained for aqueous solutions of a trivalent cationic surfactant (C0RCI3) in both water and in 150 mM NaCl solution. Use the data and the Gibbs adsorption isotherm to obtain estimates of the minimum surface area per molecule adsorbed at the air/water interface. 

A. M. Grancaric, T. Pusic, I. Soljacic, and V. Ribitsch, Influence of Electrokinetic Potential on Adsorption of Cationic Surfactants," Textile Chemist Colorist 29(12) 33 (1997). 

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